The present invention relates to a filter element wound from a plurality of filter layers.
Filter elements wound from paper layers are known, for example, from U.S. Pat. No. 5,820,646 (=EP 900,118), which discloses cylindrical filter elements having cross-sectional areas with a circular circumferential contour. This patent also discloses filter elements having a substantially rectangular circumferential contour, but the corners of the cross-sectional filter element area are rounded for manufacturing reasons. U.S. Pat. No. 5,820,646 additionally discloses the manufacture of filter elements having an oval circumferential contour. However, all the known filter elements have in common that they have a positive, outwardly curved or convex circumferential contour.